Re: [tarantool-patches] [PATCH 1/3] core/fiber: Increase default stack size

[Konstantin Osipov <kostja@tarantool.org>]

* Alexander Turenko <alexander.turenko@tarantool.org> [19/03/06 10:24]:

Alexander, we plan to make the default stack size configurable.

> On Wed, Mar 06, 2019 at 01:38:52AM +0300, Cyrill Gorcunov wrote:
> > The default 64K stack size used for years become too small
> > for modern distors (Fedora 29 and etc) where third party libraries
> > (such as ncurses) started to use 64K for own buffers and we get
> > SIGSGV early without reaching interactive console phase.
> > 
> > Thus we increase default size up to 256K which should fit
> > for common case. Later we will make this value configurable
> > to address arbitrary stack sizes without a need to rebuild
> > the code.
> > 
> > Note the values are switched to 4K page granularity for sake
> > of future modifications -- we gonna manipulate pages to
> > relax rss usage if OS allows.
> > 
> > Closes #3418
> > ---
> >  src/lib/core/fiber.c | 8 ++++----
> >  1 file changed, 4 insertions(+), 4 deletions(-)
> > 
> > diff --git a/src/lib/core/fiber.c b/src/lib/core/fiber.c
> > index abd6c6b11..d4d16c05e 100644
> > --- a/src/lib/core/fiber.c
> > +++ b/src/lib/core/fiber.c
> > @@ -92,10 +92,10 @@ static size_t page_size;
> >  static int stack_direction;
> >  
> >  enum {
> > -	/* The minimum allowable fiber stack size in bytes */
> > -	FIBER_STACK_SIZE_MINIMAL = 16384,
> > -	/* Default fiber stack size in bytes */
> > -	FIBER_STACK_SIZE_DEFAULT = 65536
> > +	/* The minimum allowable fiber stack size in 4K page */
> > +	FIBER_STACK_SIZE_MINIMAL = 4 << 12,
> > +	/* Default fiber stack size in 4K page */
> > +	FIBER_STACK_SIZE_DEFAULT = 64 << 12,
> 
> I recently looked at #3564 and observed that 256 KiB of stack is not
> enough for our http client (the wrapper around libcurl). I bisected how
> much it requeres and found that it fails with 448 KiB, but succeeds with
> 480 KiB. I just tried the following case with different
> FIBER_STACK_SIZE_DEFAULT constants on our tt-mac machine:
> 
> ./src/tar
-- 
Konstantin Osipov, Moscow, Russia, +7 903 626 22 32
http://tarantool.io - www.twitter.com/kostja_osipov